TimeSequenceStepper

time_sequence

C++ Type:std::vector<double>

Unit:(no unit assumed)

Controllable:No

Description:The values of t

(test/tests/time_steppers/timesequence_stepper/timesequence.i)

[Mesh]
  type = GeneratedMesh
  dim = 2
  xmin = -1
  xmax =  1
  ymin = -1
  ymax =  1
  nx = 2
  ny = 2
  elem_type = QUAD9
[]

[Functions]
  [./exact_fn]
    type = ParsedFunction
    expression = t*t*(x*x+y*y)
  [../]

  [./forcing_fn]
    type = ParsedFunction
    expression = 2*t*(x*x+y*y)-4*t*t
  [../]
[]

[Variables]
  [./u]
    family = LAGRANGE
    order = SECOND
  [../]
[]

[ICs]
  [./u_var]
    type = FunctionIC
    variable = u
    function = exact_fn
  [../]
[]

[Kernels]
  [./td]
    type = TimeDerivative
    variable = u
  [../]

  [./diff]
    type = Diffusion
    variable = u
  [../]

  [./ffn]
    type = BodyForce
    variable = u
    function = forcing_fn
  [../]
[]

[BCs]
  [./all]
    type = FunctionDirichletBC
    variable = u
    boundary = 'left right top bottom'
    function = exact_fn
  [../]
[]

[Executioner]
  type = Transient
  end_time = 4.0
  [./TimeStepper]
    type = TimeSequenceStepper
    time_sequence  = '0   0.85 1.3 2 4'
  [../]
[]

[Outputs]
  exodus = true
[]

(test/tests/time_steppers/time_stepper_system/time_stepper_system.i)

[Mesh]
  file = restart_test_cp/0005-mesh.cpa.gz
[]

[Variables]
  [u]
    order = CONSTANT
    family = MONOMIAL
  []
[]

[Problem]
   type = SlowProblem
   seconds_to_sleep = '0.0 0.0 0.1 0.1 0.5 0.2 0.2 0.1 0.1 0.1'
   kernel_coverage_check = false
  restart_file_base = restart_test_cp/0005
[]

[Executioner]
  type = Transient
  solve_type = NEWTON
  num_steps = 10

  [TimeSteppers]
    [LogConstDT]
      type = LogConstantDT
      log_dt = 0.2
      first_dt = 0.1
    []

    [Timesequence]
      type = TimeSequenceStepper
      time_sequence  = '0  0.12 0.2 0.5 0.6'
    []
  []
[]

[Postprocessors]
  [dt]
    type = TimestepSize
  []
[]

[Outputs]
  csv = true
  file_base='time_stepper_restart'
[]

(modules/optimization/test/tests/executioners/transient_and_adjoint/nonuniform_tstep.i)

[Mesh]
  [gmg]
    type = GeneratedMeshGenerator
    dim = 2
    xmax = 1
    ymax = 1
    nx = 10
    ny = 10
  []
[]

[Problem]
  nl_sys_names = 'nl0 adjoint'
[]

[Variables]
  [u]
  []
  [u_adjoint]
    solver_sys = adjoint
  []
[]

[Kernels]
  [time]
    type = TimeDerivative
    variable = u
  []
  [diff]
    type = Diffusion
    variable = u
  []
  [src]
    type = BodyForce
    variable = u
    value = 10
  []
  [src_adjoint]
    type = BodyForce
    variable = u_adjoint
    value = 100
  []
[]

[BCs]
  [dirichlet]
    type = DirichletBC
    variable = u
    boundary = 'top right'
    value = 0
  []
[]

[Executioner]
  type = TransientAndAdjoint
  forward_system = nl0
  adjoint_system = adjoint

  [TimeStepper]
    type = TimeSequenceStepper
    time_sequence = '0 0.1 0.2 0.4 0.7 1.1 1.4 1.6 1.7'
  []
  end_time = 1.7

  nl_rel_tol = 1e-12
  l_tol = 1e-12
[]

[Postprocessors]
  [u_avg]
    type = ElementAverageValue
    variable = u
    execute_on = 'TIMESTEP_END ADJOINT_TIMESTEP_END'
  []
  [u_adjoint_avg]
    type = ElementAverageValue
    variable = u_adjoint
    execute_on = ADJOINT_TIMESTEP_END
  []
  [inner_product]
    type = VariableInnerProduct
    variable = u
    second_variable = u_adjoint
    execute_on = ADJOINT_TIMESTEP_END
  []
[]

[Outputs]
  [forward]
    type = CSV
  []
  [adjoint]
    type = CSV
    execute_on = 'INITIAL ADJOINT_TIMESTEP_END'
  []
  [console]
    type = Console
    execute_postprocessors_on = 'INITIAL TIMESTEP_END ADJOINT_TIMESTEP_END'
  []
[]

(test/tests/mesh/add_subdomain_ids/add_subdomain_names.i)

[Problem]
  solve = false
  kernel_coverage_check = false
  material_coverage_check = false
[]

Box2_inactive_name = 'Box2_inactive'
Box3_inactive_name = 'Box3_inactive'
Box4_inactive_name = 'Box4_inactive'
inactive_domain_block_names = '${Box2_inactive_name} ${Box3_inactive_name} ${Box4_inactive_name}'

[Mesh]
  [BaseMesh]
    type = GeneratedMeshGenerator
    elem_type = TET4
    dim = 3
    nx = 4
    ny = 3
    nz = 2
    xmin = -10
    xmax = +10
    ymin = -10
    ymax = +10
    zmin = -2
    zmax = +2
  []

  [Box1]
    type = SubdomainBoundingBoxGenerator
    input = "BaseMesh"
    block_id = 1
    location = "INSIDE"
    bottom_left = "-20 -20 -2"
    top_right = "+20 +20 +2"
  []

  [Box2]
    type = SubdomainBoundingBoxGenerator
    input = "Box1"
    block_id = 2
    location = "INSIDE"
    bottom_left = "-4 -3 +3"
    top_right = "0 +3 0"
  []

  [Box3]
    type = SubdomainBoundingBoxGenerator
    input = "Box2"
    block_id = 3
    location = "INSIDE"
    bottom_left = "0 -3 +2"
    top_right = "+4 +3 0"
  []

  add_subdomain_names = ${inactive_domain_block_names}
[]

[AuxVariables]
  [dummy]
    type = MooseVariableFVReal
  []
[]

# move elements between subdomains back and forth
[UserObjects]
  [GlobalSubdomainModifier]
    type = TimedSubdomainModifier
    times = '      0.4            0.6              0.4'
    blocks_from = '2              Box2_inactive    3'
    blocks_to = '  Box2_inactive  2                Box3_inactive'
    execute_on = 'INITIAL TIMESTEP_BEGIN'
  []
[]

[Executioner]
  type = Transient

  end_time = 1.0
  [TimeSteppers]
    [BlockEventTimeStepper]
      type = TimeSequenceStepper
      time_sequence = '0.0 0.2 0.4 0.5 0.6 1.0'
    []
  []

  solve_type = 'PJFNK'
  petsc_options = '-snes_converged_reason'
  petsc_options_iname = '-pc_type -pc_factor_mat_solver_package'
  petsc_options_value = ' lu       mumps'

  nl_abs_tol = 1E-3
  nl_max_its = 400

  l_tol = 1E-3
  l_max_its = 200
[]

[Outputs]
  exodus = true
[]

(modules/phase_field/test/tests/misc/timestepmaterial.i)

[Mesh]
  type = GeneratedMesh
  dim = 2
  nx = 2
  ny = 1
[]

[Materials]
  [./time]
    type = TimeStepMaterial
    outputs = exodus
  [../]
[]

[Problem]
  solve = false
  kernel_coverage_check = false
[]

[Executioner]
  type = Transient
  num_steps = 6

  [./TimeStepper]
    type = TimeSequenceStepper
    time_sequence = '4 8 15 16 23 42'
  [../]
[]

[Outputs]
  exodus = true
  execute_on = timestep_end
[]

(modules/solid_mechanics/test/tests/dynamics/time_integration/direct_central_difference_varied_dt.i)

###########################################################
# This is a simple test with a time-dependent problem
# demonstrating the use of a central difference with a
# direct calculation of acceleration.
#
# Testing that the first and second time derivatives
# are calculated correctly using the Direct Central Difference
# method

# Testing the accuracy of the timestep averaging method within
# the Direct Central Difference method
###########################################################

[GlobalParams]
  displacements = 'disp_x disp_y'
[]

[Problem]
  extra_tag_matrices = 'mass'
[]

[Mesh]
  type = GeneratedMesh
  dim = 2
  xmin = -1
  xmax = 1
  ymin = -1
  ymax = 1
  nx = 1
  ny = 1
[]

[Variables]
  [disp_x]
  []
  [disp_y]
  []
[]

[Functions]
  #Mid-step velocities
  #0 0.00625 0.015 0.0075 0.25 0
  #Accelerations
  #0.025 0.01944 -0.01 0.48 -2.17
  [forcing_fn]
    type = PiecewiseLinear
    x = '0.0 0.1 0.5    1.0  2.0   2.01 2.23'
    y = '0.0 0.0 0.0025 0.01 0.0175 0.02 0.02'
  []
[]

[Kernels]
  [DynamicSolidMechanics]
    displacements = 'disp_x disp_y'
  []
  [massmatrix]
    type = MassMatrix
    density = density
    matrix_tags = 'mass'
    variable = disp_x
  []
  [massmatrix_y]
    type = MassMatrix
    density = density
    matrix_tags = 'mass'
    variable = disp_y
  []
[]

[Materials]
  [elasticity_tensor_block_one]
    type = ComputeIsotropicElasticityTensor
    youngs_modulus = 1e1
    poissons_ratio = 0.0
  []

  [strain_block]
    type = ComputeFiniteStrain
    displacements = 'disp_x disp_y'
    implicit = false
  []
  [stress_block]
    type = ComputeFiniteStrainElasticStress
    implicit = false
  []
  [density]
    type = GenericConstantMaterial
    prop_names = 'density'
    prop_values = 5
  []
[]

[BCs]
  [left_x]
    type = ExplicitFunctionDirichletBC
    variable = disp_x
    boundary = 'left'
    function = forcing_fn
  []
  [right_x]
    type = ExplicitFunctionDirichletBC
    variable = disp_x
    boundary = 'right'
    function = forcing_fn
  []
[]

[Executioner]
  type = Transient

  [TimeIntegrator]
    type = ExplicitMixedOrder
    mass_matrix_tag = 'mass'
    second_order_vars = 'disp_x disp_y'
  []
  [TimeStepper]
    type = TimeSequenceStepper
    time_sequence = '0.0 0.1 0.5 1.0 2.0 2.01 2.23'
  []
  start_time = 0.0
  num_steps = 6
  dt = 0.1
[]

[Postprocessors]
  [udot]
    type = ElementAverageTimeDerivative
    variable = disp_x
  []
  [udotdot]
    type = ElementAverageSecondTimeDerivative
    variable = disp_x
  []
  [u]
    type = ElementAverageValue
    variable = disp_x
  []
[]

[Outputs]
  exodus = true
[]

(test/tests/time_steppers/timesequence_stepper/restart_from_steady.i)

[Mesh]
  type = GeneratedMesh
  dim = 2
  xmin = -1
  xmax =  1
  ymin = -1
  ymax =  1
  nx = 2
  ny = 2
[]

[Problem]
    restart_file_base = steady_for_restart_out_cp/LATEST
[]

[Variables]
  [u]
  []
[]

[BCs]
  [all]
    type = DirichletBC
    variable = u
    boundary = 'left right top bottom'
    value = 0
  []
[]

[Kernels]
  [diff]
    type = Diffusion
    variable = u
  []
  [ffn]
    type = BodyForce
    variable = u
    function = 2
  []
[]

[Executioner]
  type = Transient
  end_time = 2
  # By default, will start at
  # 1 since the end time from
  # the steady executioner is 1
  start_time = 0
  [./TimeStepper]
    type = TimeSequenceStepper
    time_sequence  = '0 1 2'
  [../]
[]

(test/tests/mfem/timesteppers/mfem_multiple_timesequences.i)

[Problem]
  type = MFEMProblem
[]

[Mesh]
  type = MFEMMesh
  file = ../mesh/square.e
[]

[FESpaces]
  [H1FESpace]
    type = MFEMScalarFESpace
    fec_type = H1
    fec_order = FIRST
  []
[]

[Variables]
  [u]
    type = MFEMVariable
    fespace = H1FESpace
  []
[]

[Kernels]
  [diff]
    type = MFEMDiffusionKernel
    variable = u
    coefficient = 0.1
  []
  [time]
    type = MFEMTimeDerivativeMassKernel
    variable = u
  []
[]

[BCs]
  [left]
    type = MFEMScalarDirichletBC
    variable = u
    boundary = left
    coefficient = 0
  []
  [right]
    type = MFEMScalarDirichletBC
    variable = u
    boundary = right
    coefficient = 1
  []
[]

[Preconditioner]
  [boomeramg]
    type = MFEMHypreBoomerAMG
  []
[]

[Solver]
  type = MFEMHyprePCG
  preconditioner = boomeramg
  l_tol = 1e-8
  l_max_its = 100
[]

[Executioner]
  type = MFEMTransient
  device = cpu
  end_time = 0.8

  # Use as many different time sequence steppers as we could to test the compositionDT
  [TimeSteppers]
    [ConstDT1]
      type = ConstantDT
      dt = 0.2
    []

    [ConstDT2]
      type = ConstantDT
      dt = 0.1
    []

    [LogConstDT]
      type = LogConstantDT
      log_dt = 0.2
      first_dt = 0.1
    []

    [Timesequence1]
      type = TimeSequenceStepper
      time_sequence  = '0  0.25 0.3 0.5 0.8'
    []

    [Timesequence2]
      type = CSVTimeSequenceStepper
      file_name = timesequence.csv
      column_name = time
    []

    [Timesequence3]
      type = ExodusTimeSequenceStepper
      mesh = timesequence.e
    []
  []
[]

[Postprocessors]
  [timestep]
    type = TimePostprocessor
    execute_on = 'timestep_end'
  []
[]

[Outputs]
  csv = true
  file_base='mfem_multiple_timesequences'
[]

(test/tests/time_steppers/timesequence_stepper/timesequence.i)

[Mesh]
  type = GeneratedMesh
  dim = 2
  xmin = -1
  xmax =  1
  ymin = -1
  ymax =  1
  nx = 2
  ny = 2
  elem_type = QUAD9
[]

[Functions]
  [./exact_fn]
    type = ParsedFunction
    expression = t*t*(x*x+y*y)
  [../]

  [./forcing_fn]
    type = ParsedFunction
    expression = 2*t*(x*x+y*y)-4*t*t
  [../]
[]

[Variables]
  [./u]
    family = LAGRANGE
    order = SECOND
  [../]
[]

[ICs]
  [./u_var]
    type = FunctionIC
    variable = u
    function = exact_fn
  [../]
[]

[Kernels]
  [./td]
    type = TimeDerivative
    variable = u
  [../]

  [./diff]
    type = Diffusion
    variable = u
  [../]

  [./ffn]
    type = BodyForce
    variable = u
    function = forcing_fn
  [../]
[]

[BCs]
  [./all]
    type = FunctionDirichletBC
    variable = u
    boundary = 'left right top bottom'
    function = exact_fn
  [../]
[]

[Executioner]
  type = Transient
  end_time = 4.0
  [./TimeStepper]
    type = TimeSequenceStepper
    time_sequence  = '0   0.85 1.3 2 4'
  [../]
[]

[Outputs]
  exodus = true
[]

(test/tests/kernels/functor_kernel/functor_kernel_target.i)

[Mesh]
  type = GeneratedMesh
  dim = 2
  nx = 10
  ny = 10
[]

[Variables]
  [u]
  []
[]

[Kernels]
  [PredefinedPorepressure]
    type = FunctorKernel
    variable = 'u'
    mode = 'TARGET'
    functor_on_rhs = false
    functor = target_u
  []
[]

[Functions]
  [target_u]
    type = ParsedFunction
    expression = 'max(1, 1 + t)'
  []
[]


[Executioner]
  type = Transient
  solve_type = 'NEWTON'
  petsc_options_iname = '-pc_type -pc_hypre_type'
  petsc_options_value = 'hypre boomeramg'

  l_tol = 1e-15
  l_max_its = 50

  nl_abs_tol = 1e-16
  nl_rel_tol = 1e-16
  nl_max_its = 15

  start_time = 0.0
  end_time = 11
  dtmin = 1e-2
  [TimeSteppers]
    [TimeSequenceStepper1]
      type = TimeSequenceStepper
      time_sequence = '1 2 3 4 5 6 7 8 9 10 11'
    []
  []

[]

[Outputs]
  exodus = true
[]

(modules/phase_field/test/tests/GrandPotentialPFM/GrandPotentialMultiphase_AD.i)

[Mesh]
  type = GeneratedMesh
  dim = 2
  nx = 20
  ny = 20
  xmin = -20
  xmax = 20
  ymin = -20
  ymax = 20
[]

[GlobalParams]
  op_num = 2
  var_name_base = etab
[]

[Variables]
  [w]
  []
  [etaa0]
  []
  [etab0]
  []
  [etab1]
  []
[]

[AuxVariables]
  [bnds]
    order = FIRST
    family = LAGRANGE
  []
[]

[ICs]

  [IC_etaa0]
    type = FunctionIC
    variable = etaa0
    function = ic_func_etaa0
  []
  [IC_etab0]
    type = FunctionIC
    variable = etab0
    function = ic_func_etab0
  []
  [IC_etab1]
    type = FunctionIC
    variable = etab1
    function = ic_func_etab1
  []
  [IC_w]
    type = ConstantIC
    value = -0.05
    variable = w
  []
[]

[Functions]
  [ic_func_etaa0]
    type = ParsedFunction
    expression = 'r:=sqrt(x^2+y^2);0.5*(1.0-tanh((r-10.0)/sqrt(2.0)))'
  []
  [ic_func_etab0]
    type = ParsedFunction
    expression = 'r:=sqrt(x^2+y^2);0.5*(1.0+tanh((r-10)/sqrt(2.0)))*0.5*(1.0+tanh((y)/sqrt(2.0)))'
  []
  [ic_func_etab1]
    type = ParsedFunction
    expression = 'r:=sqrt(x^2+y^2);0.5*(1.0+tanh((r-10)/sqrt(2.0)))*0.5*(1.0-tanh((y)/sqrt(2.0)))'
  []
[]

[BCs]
[]

[Kernels]
  # Order parameter eta_alpha0
  [ACa0_bulk]
    type = ADACGrGrMulti
    variable = etaa0
    v = 'etab0 etab1'
    gamma_names = 'gab   gab'
  []
  [ACa0_sw]
    type = ADACSwitching
    variable = etaa0
    Fj_names = 'omegaa omegab'
    hj_names = 'ha     hb'
  []
  [ACa0_int]
    type = ADACInterface
    variable = etaa0
    kappa_name = kappa
    variable_L = false
  []
  [ea0_dot]
    type = ADTimeDerivative
    variable = etaa0
  []
  # Order parameter eta_beta0
  [ACb0_bulk]
    type = ADACGrGrMulti
    variable = etab0
    v = 'etaa0 etab1'
    gamma_names = 'gab   gbb'
  []
  [ACb0_sw]
    type = ADACSwitching
    variable = etab0
    Fj_names = 'omegaa omegab'
    hj_names = 'ha     hb'
  []
  [ACb0_int]
    type = ADACInterface
    variable = etab0
    kappa_name = kappa
    variable_L = false
  []
  [eb0_dot]
    type = ADTimeDerivative
    variable = etab0
  []
  # Order parameter eta_beta1
  [ACb1_bulk]
    type = ADACGrGrMulti
    variable = etab1
    v = 'etaa0 etab0'
    gamma_names = 'gab   gbb'
  []
  [ACb1_sw]
    type = ADACSwitching
    variable = etab1
    Fj_names = 'omegaa omegab'
    hj_names = 'ha     hb'
  []
  [ACb1_int]
    type = ADACInterface
    variable = etab1
    kappa_name = kappa
    variable_L = false
  []
  [eb1_dot]
    type = ADTimeDerivative
    variable = etab1
  []
  #Chemical potential
  [w_dot]
    type = ADSusceptibilityTimeDerivative
    variable = w
    f_name = chi
  []
  [Diffusion]
    type = ADMatDiffusion
    variable = w
    diffusivity = Dchi
  []
  [coupled_etaa0dot]
    type = ADCoupledSwitchingTimeDerivative
    variable = w
    v = etaa0
    Fj_names = 'rhoa rhob'
    hj_names = 'ha   hb'
    coupled_variables = 'etaa0 etab0 etab1'
  []
  [coupled_etab0dot]
    type = ADCoupledSwitchingTimeDerivative
    variable = w
    v = etab0
    Fj_names = 'rhoa rhob'
    hj_names = 'ha   hb'
    coupled_variables = 'etaa0 etab0 etab1'
  []
  [coupled_etab1dot]
    type = ADCoupledSwitchingTimeDerivative
    variable = w
    v = etab1
    Fj_names = 'rhoa rhob'
    hj_names = 'ha   hb'
    coupled_variables = 'etaa0 etab0 etab1'
  []
[]

[AuxKernels]
  [BndsCalc]
    type = BndsCalcAux
    variable = bnds
    execute_on = timestep_end
  []
[]

# enable_jit set to false in many materials to make this test start up faster.
# It is recommended to set enable_jit = true or just remove these lines for
# production runs with this model
[Materials]
  [ha]
    type = ADSwitchingFunctionMultiPhaseMaterial
    h_name = ha
    all_etas = 'etaa0 etab0 etab1'
    phase_etas = 'etaa0'
  []
  [hb]
    type = ADSwitchingFunctionMultiPhaseMaterial
    h_name = hb
    all_etas = 'etaa0 etab0 etab1'
    phase_etas = 'etab0 etab1'
  []
  [omegaa]
    type = ADDerivativeParsedMaterial
    coupled_variables = 'w'
    f_name = omegaa
    material_property_names = 'Vm ka caeq'
    expression = '-0.5*w^2/Vm^2/ka-w/Vm*caeq'
    derivative_order = 2
  []
  [omegab]
    type = ADDerivativeParsedMaterial
    coupled_variables = 'w'
    f_name = omegab
    material_property_names = 'Vm kb cbeq'
    expression = '-0.5*w^2/Vm^2/kb-w/Vm*cbeq'
    derivative_order = 2
  []
  [rhoa]
    type = ADDerivativeParsedMaterial
    coupled_variables = 'w'
    f_name = rhoa
    material_property_names = 'Vm ka caeq'
    expression = 'w/Vm^2/ka + caeq/Vm'
    derivative_order = 2
  []
  [rhob]
    type = ADDerivativeParsedMaterial
    coupled_variables = 'w'
    f_name = rhob
    material_property_names = 'Vm kb cbeq'
    expression = 'w/Vm^2/kb + cbeq/Vm'
    derivative_order = 2
  []
  [const]
    type = ADGenericConstantMaterial
    prop_names = 'kappa_c  kappa   L   D    chi  Vm   ka    caeq kb    cbeq  gab gbb mu'
    prop_values = '0        1       1.0 1.0  1.0  1.0  10.0  0.1  10.0  0.9   4.5 1.5 1.0'
  []
  [Mobility]
    type = ADDerivativeParsedMaterial
    f_name = Dchi
    material_property_names = 'D chi'
    expression = 'D*chi'
    derivative_order = 2
  []
[]

[Preconditioning]
  [SMP]
    type = SMP
    full = true
  []
[]

[Executioner]
  type = Transient
  scheme = bdf2
  solve_type = NEWTON
  petsc_options_iname = '-pc_type '
  petsc_options_value = 'lu     '
  l_tol = 1.0e-3
  nl_rel_tol = 1.0e-8
  nl_abs_tol = 1e-8
  num_steps = 2
  [TimeStepper]
    type = TimeSequenceStepper
    time_sequence = '0.1 0.21'
  []
[]

[Outputs]
  exodus = true
  file_base = GrandPotentialMultiphase_out
[]

(test/tests/time_steppers/time_stepper_system/timestepper_input_error.i)

[Mesh]
  type = GeneratedMesh
  dim = 2
  nx = 10
  ny = 10
[]

[Variables]
  [u]
  []
[]

[Kernels]
  [diff]
    type = CoefDiffusion
    variable = u
    coef = 0.1
  []
  [time]
    type = TimeDerivative
    variable = u
  []
[]

[BCs]
  [left]
    type = DirichletBC
    variable = u
    boundary = left
    value = 0
  []
  [right]
    type = DirichletBC
    variable = u
    boundary = right
    value = 1
  []
[]

[Executioner]
  type = Transient   # Here we use the Transient Executioner
  [TimeSteppers]
      type = TimeSequenceStepper
      time_sequence  = '0 43200 86400 172800 432000 864000'
  []
  start_time = 0.0
  end_time = 864000
[]

[Postprocessors]
  [timestep]
    type = TimePostprocessor
    execute_on = 'timestep_end'
  []
[]

[Outputs]
  csv = true
  file_base='multiple_timesequence'
[]

(test/tests/mfem/timesteppers/mfem_multiple_timesteppers.i)

[Problem]
  type = MFEMProblem
[]

[Mesh]
  type = MFEMMesh
  file = ../mesh/square.e
[]

[FESpaces]
  [H1FESpace]
    type = MFEMScalarFESpace
    fec_type = H1
    fec_order = FIRST
  []
[]

[Variables]
  [u]
    type = MFEMVariable
    fespace = H1FESpace
  []
[]

[Kernels]
  [diff]
    type = MFEMDiffusionKernel
    variable = u
    coefficient = 0.1
  []
  [time]
    type = MFEMTimeDerivativeMassKernel
    variable = u
  []
[]

[Functions]
  [dts]
    type = PiecewiseLinear
    x = '0   0.85 2'
    y = '0.2 0.15  0.2'
  []
[]

[BCs]
  [left]
    type = MFEMScalarDirichletBC
    variable = u
    boundary = left
    coefficient = 0
  []
  [right]
    type = MFEMScalarDirichletBC
    variable = u
    boundary = right
    coefficient = 1
  []
[]

[Preconditioner]
  [boomeramg]
    type = MFEMHypreBoomerAMG
  []
[]

[Solver]
  type = MFEMHyprePCG
  preconditioner = boomeramg
  l_tol = 1e-8
  l_max_its = 100
[]

[Executioner]
  type = MFEMTransient
  device = cpu
  end_time = 0.8
  # Use as many different time steppers as we could to test the compositionDT,
  # SolutionTimeAdaptiveDT give slightly different dt per run, set rel_err = 1e-2
  # to ensure the test won't fail due to the small difference in the high-digit.
  [TimeSteppers]
    [ConstDT1]
      type = ConstantDT
      dt = 0.2
    []

    [FunctionDT]
      type = FunctionDT
      function = dts
    []

    [LogConstDT]
      type = LogConstantDT
      log_dt = 0.2
      first_dt = 0.1
    []

    [IterationAdapDT]
      type = IterationAdaptiveDT
      dt = 0.5
    []

    [Timesequence]
      type = TimeSequenceStepper
      time_sequence  = '0  0.25 0.3 0.5 0.8'
    []
  []
[]

[Postprocessors]
  [timestep]
    type = TimePostprocessor
    execute_on = 'timestep_end'
  []
[]

[Outputs]
  csv = true
  file_base='mfem_multiple_timesteppers'
[]

(modules/phase_field/test/tests/GrandPotentialPFM/GrandPotentialMultiphase.i)

[Mesh]
  type = GeneratedMesh
  dim = 2
  nx = 20
  ny = 20
  xmin = -20
  xmax = 20
  ymin = -20
  ymax = 20
[]

[GlobalParams]
  op_num = 2
  var_name_base = etab
[]

[Variables]
  [w]
  []
  [etaa0]
  []
  [etab0]
  []
  [etab1]
  []
[]

[AuxVariables]
  [bnds]
    order = FIRST
    family = LAGRANGE
  []
[]

[ICs]

  [IC_etaa0]
    type = FunctionIC
    variable = etaa0
    function = ic_func_etaa0
  []
  [IC_etab0]
    type = FunctionIC
    variable = etab0
    function = ic_func_etab0
  []
  [IC_etab1]
    type = FunctionIC
    variable = etab1
    function = ic_func_etab1
  []
  [IC_w]
    type = ConstantIC
    value = -0.05
    variable = w
  []
[]

[Functions]
  [ic_func_etaa0]
    type = ParsedFunction
    expression = 'r:=sqrt(x^2+y^2);0.5*(1.0-tanh((r-10.0)/sqrt(2.0)))'
  []
  [ic_func_etab0]
    type = ParsedFunction
    expression = 'r:=sqrt(x^2+y^2);0.5*(1.0+tanh((r-10)/sqrt(2.0)))*0.5*(1.0+tanh((y)/sqrt(2.0)))'
  []
  [ic_func_etab1]
    type = ParsedFunction
    expression = 'r:=sqrt(x^2+y^2);0.5*(1.0+tanh((r-10)/sqrt(2.0)))*0.5*(1.0-tanh((y)/sqrt(2.0)))'
  []
[]

[BCs]
[]

[Kernels]
  # Order parameter eta_alpha0
  [ACa0_bulk]
    type = ACGrGrMulti
    variable = etaa0
    v = 'etab0 etab1'
    gamma_names = 'gab   gab'
  []
  [ACa0_sw]
    type = ACSwitching
    variable = etaa0
    Fj_names = 'omegaa omegab'
    hj_names = 'ha     hb'
    coupled_variables = 'etab0 etab1 w'
  []
  [ACa0_int]
    type = ACInterface
    variable = etaa0
    kappa_name = kappa
  []
  [ea0_dot]
    type = TimeDerivative
    variable = etaa0
  []
  # Order parameter eta_beta0
  [ACb0_bulk]
    type = ACGrGrMulti
    variable = etab0
    v = 'etaa0 etab1'
    gamma_names = 'gab   gbb'
  []
  [ACb0_sw]
    type = ACSwitching
    variable = etab0
    Fj_names = 'omegaa omegab'
    hj_names = 'ha     hb'
    coupled_variables = 'etaa0 etab1 w'
  []
  [ACb0_int]
    type = ACInterface
    variable = etab0
    kappa_name = kappa
  []
  [eb0_dot]
    type = TimeDerivative
    variable = etab0
  []
  # Order parameter eta_beta1
  [ACb1_bulk]
    type = ACGrGrMulti
    variable = etab1
    v = 'etaa0 etab0'
    gamma_names = 'gab   gbb'
  []
  [ACb1_sw]
    type = ACSwitching
    variable = etab1
    Fj_names = 'omegaa omegab'
    hj_names = 'ha     hb'
    coupled_variables = 'etaa0 etab0 w'
  []
  [ACb1_int]
    type = ACInterface
    variable = etab1
    kappa_name = kappa
  []
  [eb1_dot]
    type = TimeDerivative
    variable = etab1
  []
  #Chemical potential
  [w_dot]
    type = SusceptibilityTimeDerivative
    variable = w
    f_name = chi
    coupled_variables = '' # in this case chi (the susceptibility) is simply a constant
  []
  [Diffusion]
    type = MatDiffusion
    variable = w
    diffusivity = Dchi
    args = ''
  []
  [coupled_etaa0dot]
    type = CoupledSwitchingTimeDerivative
    variable = w
    v = etaa0
    Fj_names = 'rhoa rhob'
    hj_names = 'ha   hb'
    coupled_variables = 'etaa0 etab0 etab1'
  []
  [coupled_etab0dot]
    type = CoupledSwitchingTimeDerivative
    variable = w
    v = etab0
    Fj_names = 'rhoa rhob'
    hj_names = 'ha   hb'
    coupled_variables = 'etaa0 etab0 etab1'
  []
  [coupled_etab1dot]
    type = CoupledSwitchingTimeDerivative
    variable = w
    v = etab1
    Fj_names = 'rhoa rhob'
    hj_names = 'ha   hb'
    coupled_variables = 'etaa0 etab0 etab1'
  []
[]

[AuxKernels]
  [BndsCalc]
    type = BndsCalcAux
    variable = bnds
    execute_on = timestep_end
  []
[]

# enable_jit set to false in many materials to make this test start up faster.
# It is recommended to set enable_jit = true or just remove these lines for
# production runs with this model
[Materials]
  [ha]
    type = SwitchingFunctionMultiPhaseMaterial
    h_name = ha
    all_etas = 'etaa0 etab0 etab1'
    phase_etas = 'etaa0'
  []
  [hb]
    type = SwitchingFunctionMultiPhaseMaterial
    h_name = hb
    all_etas = 'etaa0 etab0 etab1'
    phase_etas = 'etab0 etab1'
  []
  [omegaa]
    type = DerivativeParsedMaterial
    coupled_variables = 'w'
    property_name = omegaa
    material_property_names = 'Vm ka caeq'
    expression = '-0.5*w^2/Vm^2/ka-w/Vm*caeq'
    derivative_order = 2
    enable_jit = false
  []
  [omegab]
    type = DerivativeParsedMaterial
    coupled_variables = 'w'
    property_name = omegab
    material_property_names = 'Vm kb cbeq'
    expression = '-0.5*w^2/Vm^2/kb-w/Vm*cbeq'
    derivative_order = 2
    enable_jit = false
  []
  [rhoa]
    type = DerivativeParsedMaterial
    coupled_variables = 'w'
    property_name = rhoa
    material_property_names = 'Vm ka caeq'
    expression = 'w/Vm^2/ka + caeq/Vm'
    derivative_order = 2
    enable_jit = false
  []
  [rhob]
    type = DerivativeParsedMaterial
    coupled_variables = 'w'
    property_name = rhob
    material_property_names = 'Vm kb cbeq'
    expression = 'w/Vm^2/kb + cbeq/Vm'
    derivative_order = 2
    enable_jit = false
  []
  [const]
    type = GenericConstantMaterial
    prop_names = 'kappa_c  kappa   L   D    chi  Vm   ka    caeq kb    cbeq  gab gbb mu'
    prop_values = '0        1       1.0 1.0  1.0  1.0  10.0  0.1  10.0  0.9   4.5 1.5 1.0'
  []
  [Mobility]
    type = DerivativeParsedMaterial
    property_name = Dchi
    material_property_names = 'D chi'
    expression = 'D*chi'
    derivative_order = 2
    enable_jit = false
  []
[]

[Preconditioning]
  [SMP]
    type = SMP
    full = true
  []
[]

[Executioner]
  type = Transient
  scheme = bdf2
  petsc_options_iname = '-pc_type -ksp_gmres_restart -sub_pc_type -pc_asm_overlap'
  petsc_options_value = 'asm      31                  lu           1'
  l_tol = 1.0e-3
  nl_rel_tol = 1.0e-8
  nl_abs_tol = 1e-8
  num_steps = 2
  [TimeStepper]
    type = TimeSequenceStepper
    time_sequence = '0.1 0.21'
  []
[]

[Outputs]
  exodus = true
[]

(test/tests/time_steppers/time_stepper_system/multiple_timesteppers.i)

[Mesh]
  type = GeneratedMesh
  dim = 2
  nx = 10
  ny = 10
[]

[Variables]
  [u]
  []
[]

[Kernels]
  [diff]
    type = CoefDiffusion
    variable = u
    coef = 0.1
  []
  [time]
    type = TimeDerivative
    variable = u
  []
[]

[Functions]
  [dts]
    type = PiecewiseLinear
    x = '0   0.85 2'
    y = '0.2 0.15  0.2'
  []
[]

[BCs]
  [left]
    type = DirichletBC
    variable = u
    boundary = left
    value = 0
  []
  [right]
    type = DirichletBC
    variable = u
    boundary = right
    value = 1
  []
[]

[Executioner]
  type = Transient
  end_time = 0.8
  solve_type = PJFNK
  petsc_options_iname = '-pc_type -pc_hypre_type'
  petsc_options_value = 'hypre boomeramg'
  # Use as many different time steppers as we could to test the compositionDT,
  # SolutionTimeAdaptiveDT give slightly different dt per run, set rel_err = 1e-2
  # to ensure the test won't fail due to the small difference in the high-digit.
  [TimeSteppers]
    [ConstDT1]
      type = ConstantDT
      dt = 0.2
    []

    [FunctionDT]
      type = FunctionDT
      function = dts
    []

    [LogConstDT]
      type = LogConstantDT
      log_dt = 0.2
      first_dt = 0.1
    []

    [IterationAdapDT]
      type = IterationAdaptiveDT
      dt = 0.5
    []

    [Timesequence]
      type = TimeSequenceStepper
      time_sequence  = '0  0.25 0.3 0.5 0.8'
    []

    [PPDT]
      type = PostprocessorDT
      postprocessor = PostDT
      dt = 0.1
    []
  []
[]

[Postprocessors]
  [timestep]
    type = TimePostprocessor
    execute_on = 'timestep_end'
  []

  [PostDT]
    type = ElementAverageValue
    variable = u
    execute_on = 'initial timestep_end'
  []
[]

[Outputs]
  csv = true
  file_base='multiple_timesteppers'
[]

(modules/navier_stokes/test/tests/finite_element/ins/hdg/ip/paper-cases/bfs/bfs-2d-root.i)

gamma = 1e4
degree = 2
alpha = '${fparse 10 * degree^2}'
rho = 1

[Mesh]
  [file]
    type = FileMeshGenerator
    file = coarse12.msh
  []
  second_order = true
[]

[Problem]
  type = NavierStokesProblem
  extra_tag_matrices = 'mass'
  mass_matrix = 'mass'
  set_schur_pre = A11_AND_MASS
[]

[Variables]
  [vel_x]
    family = L2_LAGRANGE
    order = SECOND
  []
  [vel_y]
    family = L2_LAGRANGE
    order = SECOND
  []
  [pressure]
    family = L2_LAGRANGE
    order = FIRST
  []
  [vel_bar_x]
    family = SIDE_HIERARCHIC
    order = SECOND
  []
  [vel_bar_y]
    family = SIDE_HIERARCHIC
    order = SECOND
  []
  [pressure_bar]
    family = SIDE_HIERARCHIC
    order = SECOND
  []
[]

[HDGKernels]
  [momentum_x_advection]
    type = AdvectionIPHDGKernel
    variable = vel_x
    face_variable = vel_bar_x
    velocity = 'velocity'
    coeff = ${rho}
  []
  [momentum_x_diffusion]
    type = NavierStokesStressIPHDGKernel
    variable = vel_x
    face_variable = vel_bar_x
    diffusivity = 'mu'
    alpha = ${alpha}
    pressure_variable = pressure
    pressure_face_variable = pressure_bar
    component = 0
  []
  [momentum_y_advection]
    type = AdvectionIPHDGKernel
    variable = vel_y
    face_variable = vel_bar_y
    velocity = 'velocity'
    coeff = ${rho}
  []
  [momentum_y_diffusion]
    type = NavierStokesStressIPHDGKernel
    variable = vel_y
    face_variable = vel_bar_y
    diffusivity = 'mu'
    alpha = ${alpha}
    pressure_variable = pressure
    pressure_face_variable = pressure_bar
    component = 1
  []
  [pressure]
    type = MassContinuityIPHDGKernel
    variable = pressure
    face_variable = pressure_bar
    interior_velocity_vars = 'vel_x vel_y'
    face_velocity_functors = 'vel_bar_x vel_bar_y'
  []

  [u_jump]
    type = MassFluxPenaltyIPHDG
    variable = vel_x
    face_variable = vel_bar_x
    face_velocity = face_velocity
    u = vel_x
    v = vel_y
    component = 0
    gamma = ${gamma}
  []
  [v_jump]
    type = MassFluxPenaltyIPHDG
    variable = vel_y
    face_variable = vel_bar_y
    face_velocity = face_velocity
    u = vel_x
    v = vel_y
    component = 1
    gamma = ${gamma}
  []
  [pb_mass]
    type = MassMatrixHDG
    variable = pressure_bar
    matrix_tags = 'mass'
    density = '${fparse -1/gamma}'
  []
[]

[BCs]
  #
  # inlet
  #
  [momentum_x_advection_inlet]
    type = AdvectionIPHDGDirichletBC
    boundary = '1'
    face_variable = vel_bar_x
    functor = u_inlet
    variable = vel_x
    velocity = velocity
    coeff = ${rho}
  []
  [momentum_x_diffusion_inlet]
    type = NavierStokesStressIPHDGDirichletBC
    boundary = '1'
    variable = vel_x
    face_variable = vel_bar_x
    pressure_variable = pressure
    pressure_face_variable = pressure_bar
    alpha = ${alpha}
    functor = 'u_inlet'
    diffusivity = 'mu'
    component = 0
  []
  [momentum_y_diffusion_inlet]
    type = NavierStokesStressIPHDGDirichletBC
    boundary = '1'
    variable = vel_y
    face_variable = vel_bar_y
    pressure_variable = pressure
    pressure_face_variable = pressure_bar
    alpha = ${alpha}
    functor = 0
    diffusivity = 'mu'
    component = 1
  []
  [mass_inlet]
    type = MassContinuityIPHDGBC
    face_variable = pressure_bar
    variable = pressure
    boundary = '1'
    face_velocity_functors = 'u_inlet 0'
    interior_velocity_vars = 'vel_x vel_y'
  []

  #
  # walls
  #
  [momentum_x_diffusion_walls]
    type = NavierStokesStressIPHDGDirichletBC
    boundary = '2'
    variable = vel_x
    face_variable = vel_bar_x
    pressure_variable = pressure
    pressure_face_variable = pressure_bar
    alpha = ${alpha}
    functor = '0'
    diffusivity = 'mu'
    component = 0
  []
  [momentum_y_diffusion_walls]
    type = NavierStokesStressIPHDGDirichletBC
    boundary = '2'
    variable = vel_y
    face_variable = vel_bar_y
    pressure_variable = pressure
    pressure_face_variable = pressure_bar
    alpha = ${alpha}
    functor = 0
    diffusivity = 'mu'
    component = 1
  []
  [mass_walls]
    type = MassContinuityIPHDGBC
    face_variable = pressure_bar
    variable = pressure
    boundary = '2'
    face_velocity_functors = '0 0'
    interior_velocity_vars = 'vel_x vel_y'
  []

  #
  # Neumann
  #
  [momentum_x_advection_neumann]
    type = AdvectionIPHDGOutflowBC
    boundary = '3'
    constrain_lm = false
    face_variable = vel_bar_x
    variable = vel_x
    velocity = velocity
    coeff = ${rho}
  []
  [momentum_y_advection_neumann]
    type = AdvectionIPHDGOutflowBC
    boundary = '3'
    constrain_lm = false
    face_variable = vel_bar_y
    variable = vel_y
    velocity = velocity
    coeff = ${rho}
  []
  [momentum_x_diffusion_neumann]
    type = NavierStokesStressIPHDGPrescribedTractionBC
    boundary = '3'
    component = 0
    diffusivity = 'mu'
    face_variable = vel_bar_x
    prescribed_normal_flux = 0
    pressure_face_variable = pressure_bar
    pressure_variable = pressure
    variable = vel_x
    alpha = ${alpha}
  []
  [momentum_y_diffusion_neumann]
    type = NavierStokesStressIPHDGPrescribedTractionBC
    boundary = '3'
    component = 1
    diffusivity = 'mu'
    face_variable = vel_bar_y
    prescribed_normal_flux = 0
    pressure_face_variable = pressure_bar
    pressure_variable = pressure
    variable = vel_y
    alpha = ${alpha}
  []
  [mass_neumann]
    type = MassContinuityIPHDGBC
    face_variable = pressure_bar
    variable = pressure
    boundary = '3'
    face_velocity_functors = 'vel_bar_x vel_bar_y'
    interior_velocity_vars = 'vel_x vel_y'
  []

  [pb_mass]
    type = MassMatrixIntegratedBC
    variable = pressure_bar
    matrix_tags = 'mass'
    boundary = '1 2 3'
    density = '${fparse -1/gamma}'
  []

  [u_jump_walls]
    type = MassFluxPenaltyBC
    variable = vel_x
    face_variable = vel_bar_x
    u = vel_x
    v = vel_y
    component = 0
    boundary = '2'
    gamma = ${gamma}
    face_velocity = vel_walls
    dirichlet_boundary = true
  []
  [v_jump_walls]
    type = MassFluxPenaltyBC
    variable = vel_y
    face_variable = vel_bar_y
    u = vel_x
    v = vel_y
    component = 1
    boundary = '2'
    gamma = ${gamma}
    face_velocity = vel_walls
    dirichlet_boundary = true
  []
  [u_jump_inlet]
    type = MassFluxPenaltyBC
    variable = vel_x
    face_variable = vel_bar_x
    u = vel_x
    v = vel_y
    component = 0
    boundary = '1'
    gamma = ${gamma}
    face_velocity = vel_inlet
    dirichlet_boundary = true
  []
  [v_jump_inlet]
    type = MassFluxPenaltyBC
    variable = vel_y
    face_variable = vel_bar_y
    u = vel_x
    v = vel_y
    component = 1
    boundary = '1'
    gamma = ${gamma}
    face_velocity = vel_inlet
    dirichlet_boundary = true
  []
  [u_jump_outlet]
    type = MassFluxPenaltyBC
    variable = vel_x
    face_variable = vel_bar_x
    u = vel_x
    v = vel_y
    component = 0
    boundary = '3'
    gamma = ${gamma}
    face_velocity = face_velocity
    dirichlet_boundary = false
  []
  [v_jump_outlet]
    type = MassFluxPenaltyBC
    variable = vel_y
    face_variable = vel_bar_y
    u = vel_x
    v = vel_y
    component = 1
    boundary = '3'
    gamma = ${gamma}
    face_velocity = face_velocity
    dirichlet_boundary = false
  []
[]

[Materials]
  [vel]
    type = ADVectorFromComponentVariablesMaterial
    vector_prop_name = 'velocity'
    u = vel_x
    v = vel_y
  []
  [mu]
    type = ADParsedMaterial
    functor_names = 'reynolds'
    functor_symbols = 'reynolds'
    property_name = 'mu'
    expression = '1 / reynolds'
  []
[]

[Functions]
  [u_inlet]
    type = ParsedFunction
    expression = '4*(2-y)*(y-1)'
  []
  [reynolds]
    type = ParsedFunction
    expression = 't'
  []
[]

[FunctorMaterials]
  [face_velocity]
    type = ADGenericVectorFunctorMaterial
    prop_names = face_velocity
    prop_values = 'vel_bar_x vel_bar_y 0'
  []
  [vel_inlet]
    type = GenericVectorFunctorMaterial
    prop_names = vel_inlet
    prop_values = 'u_inlet 0 0'
  []
  [vel_walls]
    type = GenericVectorFunctorMaterial
    prop_names = vel_walls
    prop_values = '0 0 0'
  []
[]

[Postprocessors]
  [reynolds]
    type = FunctionValuePostprocessor
    function = reynolds
  []
  [vel_mag_avg]
    type = ElementAverageValue
    variable = vel_mag
  []
[]

[Executioner]
  type = Transient
  solve_type = 'PJFNK'
  petsc_options = '-nl0_condensed_ksp_view'
  petsc_options_iname = '-ksp_type'
  petsc_options_value = 'preonly'
  nl_abs_tol = 1e-7
  [TimeStepper]
    type = TimeSequenceStepper
    time_sequence = '1 10 50 100 150 200 250 350 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400 2600 2800 3000 3200 3400 3600 3800 4000 4200 4400 4600 4800 5000 5200 5400 5600 5800 6000 6200 6400 6600 6800 7000 7200 7400 7600 7800 8000 8200 8400 8600 8800 9000 9200 9400 9600 9800 10000'
    use_last_t_for_end_time = true
  []
  abort_on_solve_fail = true
[]

[Outputs]
  print_linear_residuals = false
  exodus = false
  checkpoint = true
  perf_graph = true
  csv = true
[]

[AuxVariables]
  [vel_mag]
    family = L2_LAGRANGE
    order = SECOND
  []
[]

[AuxKernels]
  [vel_mag]
    type = VectorMagnitudeAux
    variable = vel_mag
    x = vel_x
    y = vel_y
  []
[]

(test/tests/time_steppers/timesequence_stepper/timesequence_restart1.i)

[Mesh]
  type = GeneratedMesh
  dim = 2
  xmin = -1
  xmax =  1
  ymin = -1
  ymax =  1
  nx = 2
  ny = 2
  elem_type = QUAD9
[]

[Functions]
  [./exact_fn]
    type = ParsedFunction
    expression = t*t*(x*x+y*y)
  [../]

  [./forcing_fn]
    type = ParsedFunction
    expression = 2*t*(x*x+y*y)-4*t*t
  [../]
[]

[Variables]
  [./u]
    family = LAGRANGE
    order = SECOND
  [../]
[]

[ICs]
  [./u_var]
    type = FunctionIC
    variable = u
    function = exact_fn
  [../]
[]

[Kernels]
  [./td]
    type = TimeDerivative
    variable = u
  [../]

  [./diff]
    type = Diffusion
    variable = u
  [../]

  [./ffn]
    type = BodyForce
    variable = u
    function = forcing_fn
  [../]
[]

[BCs]
  [./all]
    type = FunctionDirichletBC
    variable = u
    boundary = 'left right top bottom'
    function = exact_fn
  [../]
[]

[Executioner]
  type = Transient
  end_time = 4.0
  [./TimeStepper]
    type = TimeSequenceStepper
    time_sequence  = '0   0.85 1.3 2 4'
  [../]
[]

[Outputs]
  exodus = true
  [./checkpoint]
    type = Checkpoint
    num_files = 4
  [../]
[]

(test/tests/time_steppers/timesequence_stepper/timesequence_restart2.i)

[Mesh]
  file = timesequence_restart1_cp/0002-mesh.cpa.gz
[]

[Problem]
  restart_file_base = timesequence_restart1_cp/0002
  # There is an initial conditions overwriting the restart on the nonlinear variable u
  # As you can see in the gold file, this makes the initial step output be from the
  # initial condition
  allow_initial_conditions_with_restart = true
[]

[Functions]
  [exact_fn]
    type = ParsedFunction
    expression = t*t*(x*x+y*y)
  []

  [forcing_fn]
    type = ParsedFunction
    expression = 2*t*(x*x+y*y)-4*t*t
  []
[]

[Variables]
  [u]
    family = LAGRANGE
    order = SECOND
  []
[]

[ICs]
  [u_var]
    type = FunctionIC
    variable = u
    function = exact_fn
  []
[]

[Kernels]
  [td]
    type = TimeDerivative
    variable = u
  []

  [diff]
    type = Diffusion
    variable = u
  []

  [ffn]
    type = BodyForce
    variable = u
    function = forcing_fn
  []
[]

[BCs]
  [all]
    type = FunctionDirichletBC
    variable = u
    boundary = 'left right top bottom'
    function = exact_fn
  []
[]

[Executioner]
  type = Transient
  end_time = 4.0
  [TimeStepper]
    type = TimeSequenceStepper
    time_sequence = '0   0.85 1.3 2 4'
  []
[]

[Outputs]
  exodus = true
[]

(modules/navier_stokes/test/tests/finite_element/ins/hdg/ip/paper-cases/lid-driven/lid-driven-root.i)

rho = 1
l = 1
U = 1
n = 32
gamma = 1e4
degree = 2
alpha = '${fparse 10 * degree^2}'

[Mesh]
  [gen]
    type = GeneratedMeshGenerator
    dim = 2
    xmin = 0
    xmax = ${l}
    ymin = 0
    ymax = ${l}
    nx = ${n}
    ny = ${n}
    elem_type = TRI6
  []
[]

[Problem]
  type = NavierStokesProblem
  extra_tag_matrices = 'mass'
  mass_matrix = 'mass'
  set_schur_pre = A11_AND_MASS
[]

[Variables]
  [vel_x]
    family = L2_LAGRANGE
    order = SECOND
  []
  [vel_y]
    family = L2_LAGRANGE
    order = SECOND
  []
  [pressure]
    family = L2_LAGRANGE
    order = FIRST
  []
  [vel_bar_x]
    family = SIDE_HIERARCHIC
    order = SECOND
  []
  [vel_bar_y]
    family = SIDE_HIERARCHIC
    order = SECOND
  []
  [pressure_bar]
    family = SIDE_HIERARCHIC
    order = SECOND
  []
[]

[HDGKernels]
  [momentum_x_convection]
    type = AdvectionIPHDGKernel
    variable = vel_x
    face_variable = vel_bar_x
    velocity = 'velocity'
    coeff = ${rho}
  []
  [momentum_x_diffusion]
    type = NavierStokesStressIPHDGKernel
    variable = vel_x
    face_variable = vel_bar_x
    diffusivity = 'mu'
    alpha = ${alpha}
    pressure_variable = pressure
    pressure_face_variable = pressure_bar
    component = 0
  []
  [momentum_y_convection]
    type = AdvectionIPHDGKernel
    variable = vel_y
    face_variable = vel_bar_y
    velocity = 'velocity'
    coeff = ${rho}
  []
  [momentum_y_diffusion]
    type = NavierStokesStressIPHDGKernel
    variable = vel_y
    face_variable = vel_bar_y
    diffusivity = 'mu'
    alpha = ${alpha}
    pressure_variable = pressure
    pressure_face_variable = pressure_bar
    component = 1
  []

  [pressure]
    type = MassContinuityIPHDGKernel
    variable = pressure
    face_variable = pressure_bar
    interior_velocity_vars = 'vel_x vel_y'
    face_velocity_functors = 'vel_bar_x vel_bar_y'
  []

  [u_jump]
    type = MassFluxPenaltyIPHDG
    variable = vel_x
    face_variable = vel_bar_x
    u = vel_x
    v = vel_y
    component = 0
    gamma = ${gamma}
    face_velocity = face_velocity
  []
  [v_jump]
    type = MassFluxPenaltyIPHDG
    variable = vel_y
    face_variable = vel_bar_y
    u = vel_x
    v = vel_y
    component = 1
    gamma = ${gamma}
    face_velocity = face_velocity
  []
  [pb_mass]
    type = MassMatrixHDG
    variable = pressure_bar
    matrix_tags = 'mass'
    density = '${fparse -1/gamma}'
  []
[]

[BCs]
  [momentum_x_diffusion_walls]
    type = NavierStokesStressIPHDGDirichletBC
    boundary = 'left bottom right'
    variable = vel_x
    face_variable = vel_bar_x
    pressure_variable = pressure
    pressure_face_variable = pressure_bar
    alpha = ${alpha}
    functor = '0'
    diffusivity = 'mu'
    component = 0
  []
  [momentum_x_diffusion_top]
    type = NavierStokesStressIPHDGDirichletBC
    boundary = 'top'
    variable = vel_x
    face_variable = vel_bar_x
    pressure_variable = pressure
    pressure_face_variable = pressure_bar
    alpha = ${alpha}
    functor = '${U}'
    diffusivity = 'mu'
    component = 0
  []
  [momentum_y_diffusion_all]
    type = NavierStokesStressIPHDGDirichletBC
    boundary = 'left bottom right top'
    variable = vel_y
    face_variable = vel_bar_y
    pressure_variable = pressure
    pressure_face_variable = pressure_bar
    alpha = ${alpha}
    functor = '0'
    diffusivity = 'mu'
    component = 1
  []

  [pressure_walls]
    type = MassContinuityIPHDGBC
    face_variable = pressure_bar
    variable = pressure
    boundary = 'left bottom right'
    face_velocity_functors = '0 0'
    interior_velocity_vars = 'vel_x vel_y'
  []
  [pressure_lid]
    type = MassContinuityIPHDGBC
    face_variable = pressure_bar
    variable = pressure
    boundary = 'top'
    face_velocity_functors = '${U} 0'
    interior_velocity_vars = 'vel_x vel_y'
  []

  [pb_mass]
    type = MassMatrixIntegratedBC
    variable = pressure_bar
    matrix_tags = 'mass'
    boundary = 'left right bottom top'
    density = '${fparse -1/gamma}'
  []

  [u_jump_walls]
    type = MassFluxPenaltyBC
    variable = vel_x
    face_variable = vel_bar_x
    u = vel_x
    v = vel_y
    component = 0
    boundary = 'left right bottom'
    gamma = ${gamma}
    face_velocity = walls
    dirichlet_boundary = true
  []
  [v_jump_walls]
    type = MassFluxPenaltyBC
    variable = vel_y
    face_variable = vel_bar_y
    u = vel_x
    v = vel_y
    component = 1
    boundary = 'left right bottom'
    gamma = ${gamma}
    face_velocity = walls
    dirichlet_boundary = true
  []
  [u_jump_top]
    type = MassFluxPenaltyBC
    variable = vel_x
    face_variable = vel_bar_x
    u = vel_x
    v = vel_y
    component = 0
    boundary = 'top'
    gamma = ${gamma}
    face_velocity = top_vel
    dirichlet_boundary = true
  []
  [v_jump_top]
    type = MassFluxPenaltyBC
    variable = vel_y
    face_variable = vel_bar_y
    u = vel_x
    v = vel_y
    component = 1
    boundary = 'top'
    gamma = ${gamma}
    face_velocity = top_vel
    dirichlet_boundary = true
  []
[]

[Functions]
  [reynolds]
    type = ParsedFunction
    expression = 't'
  []
[]

[FunctorMaterials]
  [face_velocity]
    type = ADGenericVectorFunctorMaterial
    prop_names = face_velocity
    prop_values = 'vel_bar_x vel_bar_y 0'
  []
  [top]
    type = GenericVectorFunctorMaterial
    prop_names = top_vel
    prop_values = '${U} 0 0'
  []
  [walls]
    type = GenericVectorFunctorMaterial
    prop_names = walls
    prop_values = '0 0 0'
  []
[]

[Materials]
  [const]
    type = ADGenericConstantMaterial
    prop_names = 'rho'
    prop_values = '${rho}'
  []
  [vel]
    type = ADVectorFromComponentVariablesMaterial
    vector_prop_name = 'velocity'
    u = vel_x
    v = vel_y
  []
  [mu]
    type = ADParsedMaterial
    functor_names = 'reynolds'
    functor_symbols = 'reynolds'
    property_name = 'mu'
    expression = '${U} * ${l} / reynolds'
  []
[]

[Executioner]
  type = Transient
  solve_type = 'PJFNK'
  petsc_options = '-nl0_condensed_ksp_view'
  petsc_options_iname = '-ksp_type'
  petsc_options_value = 'preonly'
  nl_abs_tol = 1e-7
  [TimeStepper]
    type = TimeSequenceStepper
    time_sequence = '1 10 50 100 150 200 250 350 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400 2600 2800 3000 3200 3400 3600 3800 4000 4200 4400 4600 4800 5000 5200 5400 5600 5800 6000 6200 6400 6600 6800 7000 7200 7400 7600 7800 8000 8200 8400 8600 8800 9000 9200 9400 9600 9800 10000'
    use_last_t_for_end_time = true
  []
  abort_on_solve_fail = true
[]

[Outputs]
  print_linear_residuals = 'false'
  exodus = false
  checkpoint = true
  perf_graph = true
  [csv]
    type = CSV
    hide = 'pressure_average'
  []
[]

[Postprocessors]
  [Re]
    type = FunctionValuePostprocessor
    function = 'reynolds'
  []
  [pressure_average]
    type = ElementAverageValue
    variable = pressure
  []
  [vel_mag_avg]
    type = ElementAverageValue
    variable = vel_mag
  []
[]

[AuxVariables]
  [vel_mag]
    family = L2_LAGRANGE
    order = SECOND
  []
[]

[AuxKernels]
  [vel_mag]
    type = VectorMagnitudeAux
    variable = vel_mag
    x = vel_x
    y = vel_y
  []
[]

[Correctors]
  [set_pressure]
    type = NSPressurePin
    pin_type = 'average'
    variable = pressure
    pressure_average = 'pressure_average'
  []
[]

(test/tests/time_steppers/timesequence_stepper/timesequence_restart_failure.i)

[Mesh]
  file = timesequence_restart_failure1_cp/0002-mesh.cpa.gz
[]

[Problem]
  restart_file_base = timesequence_restart_failure1_cp/0002
  # There is an initial conditions overwriting the restart on the nonlinear variable u
  # As you can see in the gold file, this makes the initial step output be from the
  # initial condition
  allow_initial_conditions_with_restart = true
[]

[Functions]
  [exact_fn]
    type = ParsedFunction
    expression = t*t*(x*x+y*y)
  []

  [forcing_fn]
    type = ParsedFunction
    expression = 2*t*(x*x+y*y)-4*t*t
  []
[]

[Variables]
  [u]
    family = LAGRANGE
    order = SECOND
  []
[]

[ICs]
  [u_var]
    type = FunctionIC
    variable = u
    function = exact_fn
  []
[]

[Kernels]
  [td]
    type = TimeDerivative
    variable = u
  []

  [diff]
    type = Diffusion
    variable = u
  []

  [ffn]
    type = BodyForce
    variable = u
    function = forcing_fn
  []
[]

[BCs]
  [all]
    type = FunctionDirichletBC
    variable = u
    boundary = 'left right top bottom'
    function = exact_fn
  []
[]

[Executioner]
  type = Transient
  end_time = 4.0
  [TimeStepper]
    type = TimeSequenceStepper
    time_sequence = '0   0.85 1.2 1.3 2 4'
  []
[]

[Outputs]
  exodus = true
[]

(test/tests/time_steppers/time_stepper_system/multiple_timesequences.i)

[Mesh]
  type = GeneratedMesh
  dim = 2
  nx = 10
  ny = 10
[]

[Variables]
  [u]
  []
[]

[Kernels]
  [diff]
    type = CoefDiffusion
    variable = u
    coef = 0.1
  []
  [time]
    type = TimeDerivative
    variable = u
  []
[]

[BCs]
  [left]
    type = DirichletBC
    variable = u
    boundary = left
    value = 0
  []
  [right]
    type = DirichletBC
    variable = u
    boundary = right
    value = 1
  []
[]

[Executioner]
  type = Transient
  end_time = 0.8
  solve_type = PJFNK
  petsc_options_iname = '-pc_type -pc_hypre_type'
  petsc_options_value = 'hypre boomeramg'
  # Use as many different time sequence steppers as we could to test the compositionDT
  [TimeSteppers]
    [ConstDT1]
      type = ConstantDT
      dt = 0.2
    []

    [ConstDT2]
      type = ConstantDT
      dt = 0.1
    []

    [LogConstDT]
      type = LogConstantDT
      log_dt = 0.2
      first_dt = 0.1
    []

    [Timesequence1]
      type = TimeSequenceStepper
      time_sequence  = '0  0.25 0.3 0.5 0.8'
    []

    [Timesequence2]
      type = CSVTimeSequenceStepper
      file_name = timesequence.csv
      column_name = time
    []

    [Timesequence3]
      type = ExodusTimeSequenceStepper
      mesh = timesequence.e
    []
  []
[]

[Postprocessors]
  [timestep]
    type = TimePostprocessor
    execute_on = 'timestep_end'
  []
[]

[Outputs]
  csv = true
  file_base='multiple_timesequences'
[]

(test/tests/time_steppers/timesequence_stepper/timesequence_restart3.i)

[Mesh]
  file = timesequence_restart1_cp/0002-mesh.cpa.gz
[]

[Problem]
  restart_file_base = timesequence_restart1_cp/0002
  # There is an initial conditions overwriting the restart on the nonlinear variable u
  # As you can see in the gold file, this makes the initial step output be from the
  # initial condition
  allow_initial_conditions_with_restart = true
[]

[Functions]
  [exact_fn]
    type = ParsedFunction
    expression = t*t*(x*x+y*y)
  []

  [forcing_fn]
    type = ParsedFunction
    expression = 2*t*(x*x+y*y)-4*t*t
  []
[]

[Variables]
  [u]
    family = LAGRANGE
    order = SECOND
  []
[]

[ICs]
  [u_var]
    type = FunctionIC
    variable = u
    function = exact_fn
  []
[]

[Kernels]
  [td]
    type = TimeDerivative
    variable = u
  []

  [diff]
    type = Diffusion
    variable = u
  []

  [ffn]
    type = BodyForce
    variable = u
    function = forcing_fn
  []
[]

[BCs]
  [all]
    type = FunctionDirichletBC
    variable = u
    boundary = 'left right top bottom'
    function = exact_fn
  []
[]

[Executioner]
  type = Transient
  end_time = 4.5
  [TimeStepper]
    type = TimeSequenceStepper
    time_sequence = '0   0.85 1.3 1.9 2 4 4.5'
  []
[]

[Outputs]
  exodus = true
[]

(test/tests/time_steppers/time_stepper_system/time_stepper_system_restart.i)

[Mesh]
  type = GeneratedMesh
  dim = 1
[]

[Problem]
  solve = false
[]

[Executioner]
  type = Transient
  solve_type = NEWTON
  num_steps = 5

  [TimeSteppers]
    [SolutionTimeAdaptiveDT]
      type = SolutionTimeAdaptiveDTTest
      dt = 0.5
      fake_wall_time_sequence = '100 100 200 200 600 300'
    []

    [LogConstDT]
      type = LogConstantDT
      log_dt = 0.2
      first_dt = 0.1
    []

    [Timesequence]
      type = TimeSequenceStepper
      time_sequence = '0  0.12 0.2 0.5 0.6'
    []
  []
[]

[Postprocessors]
  [dt]
    type = TimestepSize
  []
[]

[Outputs]
  [checkpoint]
    type = Checkpoint
    num_files = 5
  []
  file_base = 'restart_test'
[]

(test/tests/time_steppers/timesequence_stepper/timesequence_last_dt.i)

[Mesh]
  type = GeneratedMesh
  dim = 1
[]

[Problem]
  solve = false
[]

[Executioner]
  type = Transient
  num_steps = 6
  [TimeStepper]
    type = TimeSequenceStepper
    time_sequence = '0 1 3 4 8'
    use_last_dt_after_last_t = true
  []
[]

[Postprocessors]
  [dt]
    type = TimestepSize
  []
[]

[Outputs]
  csv = true
[]

(test/include/timesteppers/TimeSequenceStepperFailTest.h)

// This file is part of the MOOSE framework
// https://mooseframework.inl.gov
//
// All rights reserved, see COPYRIGHT for full restrictions
// https://github.com/idaholab/moose/blob/master/COPYRIGHT
//
// Licensed under LGPL 2.1, please see LICENSE for details
// https://www.gnu.org/licenses/lgpl-2.1.html

#pragma once

#include "TimeSequenceStepper.h"

/**
 * Exactly the same as TimeSequenceStepper, but fails at predetermined
 * timesteps.
 */
class TimeSequenceStepperFailTest : public TimeSequenceStepper
{
public:
  static InputParameters validParams();

  TimeSequenceStepperFailTest(const InputParameters & parameters);

  virtual void step() override;

protected:
  /// stores a copy of the original sequence of time points, is not updated due to failures.
  std::vector<Real> _original_time_sequence;
};